The Day We Lost the H-Bomb: Cold War, Hot Nukes, and the Worst Nuclear Weapons Disaster in History

The “alpha type” radiation that Ramirez had been warned about can be either harmless or lethal, depending on where it goes. Alpha particles — two protons and two neutrons — are given off by radioactive plutonium and uranium as they decay into more stable elements. These particles are relatively large and slow, so they can't travel very far or push their way through obstacles. An alpha particle shot into the air won't usually travel much farther than an inch and can be blocked by a sheet of paper.

If alpha particles land on human skin, they won't penetrate the dead layer of cells on the surface and will sit there until scrubbed off. When, however, alpha particles get into the bloodstream — usually because someone inhales them — they can be lethal. The large particles barge through the body's cells like a bull through a china shop, breaking DNA and causing genetic mutations that can lead to cancer. They are especially dangerous when inhaled into the delicate tissue of the lungs. There, alpha particles can come into direct contact with cells, wreaking havoc.

Ramirez, standing on the edge of the crater, didn't know any of this. He called to the rest of the crew, and they came running over. One man got to work with something that looked like a Geiger counter.

Ramirez stayed out of the way.

If he had looked up into the sky right around that time, Ramirez would have seen two thin vapor trails appear far overhead, converge, and separate. The morning's Chrome Dome rendezvous went off without incident. The Cold War was proceeding on schedule.

Around 10:30 a.m., just after Ramirez found bomb number two, other airmen spotted a third. Bomb number three lay in a plowed field at the base of a wall, near the house of a shopkeeper named José López Flores, “Pepe” to his friends. At least three different stories tell who found this bomb and how. The first story says that the Guardia Civil had told Sergeant Howe — the first airman to see bomb number one the previous day — about a bomb lying near a garden wall, which Howe then tracked down. The second story tells of an unidentified airman, stopping to urinate near a stone wall, who happened to look left and saw a bomb protruding from a crater.

Both of the stories were hogwash to Pepe López himself, who knew that he had found the bomb the previous day. After the two planes collided in the sky, López heard a blast and ran outside. His aged uncle lay in the dust, knocked to the ground by the shock of the explosion. He helped the old man up, made sure he was okay, and led him back into the house. Then he went off to explore the damage. Walking over to the stone wall, he saw a half-burned parachute. A small brush fire burned nearby, and López smelled acrid smoke, the way a gun smells after a shot has been fired. Taking a closer look, the shopkeeper saw a bulky shape under the parachute. Worried that it might be a dead or injured pilot, he rushed to pull the parachute aside.